Passive ventricular support devices and methods of using them

ABSTRACT

This is a surgical device and a method of using it. In particular, the device is one for supporting or constraining at least some part of the epicardial surface of the heart during a portion of the heartbeat, in particular during diastoly. This device may be used to assist in the treatment of congestive heart failure. The device, generically, is an enclosure having an interior and an exterior. The interior surface is preferably made in such a way that it tends not to or does not form adhesions with or accept ingrowth with the myocardial tissue of the epicardium. The device preferably has at least on rib-like structural member. The rib component may extend from end-to end or preferably extends helically around the heart, preferably with at least one revolution. The device may be configured to be self-adherent, i.e., preferably adherent only to itself, and to form a unitary support in the pericardial space after installation. This device helps to prevent further declination of the heart during congestive heart failure. The device is preferably introduced into the pericardial space and onto the surface of the epicardium using transcutaneous or minimally invasive techniques.

FIELD OF THE INVENTION

[0001] This invention is a surgical device and a method of using it. Inparticular, the device is one for supporting or constraining at leastsome part of the epicardial surface of the heart during a portion of theheartbeat, in particular during the diastolic cycle. This device may beused to assist in the treatment of congestive heart failure. The device,generically, is an enclosure having an interior and an exterior. Theinterior surface is preferably made in such a way that it tends not toform or does not form adhesions with or accept ingrowth with themyocardial tissue of the epicardium. The device preferably has at leastone rib-like structural member extending for a length of the device. Therib component may extend from end-to-end or preferably extends helicallyaround the heart, generally with at least one revolution. The device maybe configured to be self-adherent, i.e., adherent only to itself, and toform after implantation, a unitary support in the pericardial space.This device helps to prevent further declination of the heart duringcongestive heart failure. The device is preferably introduced into thepericardial space and onto the surface of the epicardium usingtranscutaneous or minimally invasive techniques.

BACKGROUND OF THE INVENTION

[0002] Congestive Heart Failure (“CHF”), or simply “Heart Failure” is aprogressive path found in many forms of heart disease. In general, it isa condition in which the heart is unable to pump blood at a ratesufficient for the supply of nutrients to metabolizing tissues. Thereare many specific disease states leading to CHF, but each typicallyresults in the dilatation of the ventricles. Various etiologies for CHFare viral and ischemic and, of course, idiopathic. Variously, myocardialinjury or chronic volume overload generally are thought to cause thiscourse of ventricular dilatation. The typical adaptation processundertaken by the stressed heart muscle is not achieved during CHF and,instead of gaining a stronger heart muscle, the heart instead getslarger as it attempts to adapt to its increased volume load.

[0003] Chronic pressure overload causes another response mechanism todevelop. Specifically, hypertrophy of the heart muscle, entailing anincrease both in the size of individual muscle cells and in overallmuscle mass, begins to occur. Although this response helps the heart toovercome higher pressure, it has limitations and is associated withvarious structural and biochemical changes that have deleterious longterm effects.

[0004] Additionally, system-wide vascular constriction occurs during thecourse of CHF. The constriction causes blood flow to be redistributed sothat certain regions and systems have a reduced blood supply, e.g.,skeletal muscle, kidneys, and skin. These regions do not producesignificant amounts of vasodilating metabolites. In contrast, the brainand heart have high metabolic rates and produce a greater amount ofvasodilators. Consequently, the latter organs receive a higherproportion of the restricted blood supply.

[0005] Therapy for CHF is staged. Correction of reversible causativefactors is the first line of offense. Treatment of bradyarrhythmias,perhaps by use of an artificial pacemaker or by provision of anappropriate drug such as digitalis, can help alleviate CHF. CHF thatcontinues after correction of such reversible causes is often treatedwith a regime of salt restriction, vasodilators, diuretics, and thelike. Bed rest to increase venous return to the heart and move fluidfrom the periphery is often helpful. As noted above, digitalis has beenan important drug for increasing cardiac output in persons with specifictypes of CHF. It has been used for over 200 years. Other drugs used fortreatment of CHF include beta-adrenergic agonists such asnorepinephrine, epinephrine, and isoproterenol. Each stimulate cardiacbeta-adrenergic receptors. Dopamine and dobutamine are also used.Various diuretics and vasodilators for variously dilating both veins andarteries are used, each for slightly different reasons based on thedetected manifestation of the CHF in the heart.

[0006] Few interventional or surgical pathways for alleviation of CHFare currently widely practiced. Indeed, the only permanent treatment forCHF is a heart transplant.

[0007] One surgical procedure known as cardiomyoplasty is used for earlystage CHF. In that procedure, a muscle taken from the shoulder (thelatissimus dorsi) is wrapped around the heart. The added muscle is pacedsynchronously with the ventricular systole. This procedure is highlyinvasive since it requires a sternotomy to access the heart. Some havesuggested that the benefits of the procedure are due more to remodelingof the heart uscle rather than mere placement of a paced muscle aroundthe heart.

[0008] There are a variety of devices tha may be applied to the heartfor treatment of CHF. U.S. patents owned by Abiomed (U.S. Pat. Nos.6,224,540; 5,800,528; 5,643,172) generally show a girdle-like devicesituated to provide structure to a failing heart. U.S. patents owned byAcorn Cardiovascular, Inc. (U.S. Pat. Nos. 6,241,654; 6,230,714;6,193,648; 6,174,279; 6,169,922; 6,165,122; 6,165,121; 6,155,972;6,126,590; 6,123,662; 6,085,754; 6,077,218; 5,702,343) show variousdevices, also for treatment of CHF, that typically include a meshsock-like device placed around the myocardial wall. U.S. patents toMyocor, Inc. (U.S. Pat. No. 6,264,602; 6,261,222; 6,260,552; 6,183,411;6,165,120; 6,165,119; 6,162,168; 6,077,214; 6,059,715; 6,050,936;6,045,497; 5,961,440) show devices for treatment of CHF generally usingcomponents that pierce the ventricular wall.

[0009] None of the documents mentioned just above describe in any waythe devices and methods disclosed herein.

SUMMARY OF THE INVENTION

[0010] This device is a passive support for constraining epicardialexpansion past a predetermined limit. It generally is a flexibleenclosure and conforms to the shape of at least a portion of theenclosed epicardium. Preferably, the support member is made up of atleast one rib separated by and spaced by webbing. The ribs typicallyhave a flexibility differing than the webbing flexibility. The ribmembers may be multiple or single, helical or longitudinal, and of avariety of cross-sections, e.g., ribbon-like (with a width-thicknessratio greater than about two, preferably greater than about seven),inflatable (perhaps incrementally inflatable), round, semicircular, orother convenient shape. The rib members may be zigzag in shape, perhapswith adjacent points that are connected. The ribs may be joined at theapical end or not. Where webbing joins the rib members, the webbing maybe a woven fabric (perhaps open weave), a non-woven fabric, one or moreribbons, one or more fibers, etc. The webbing may be an elastic materialor a substantially inelastic material.

[0011] The device may be a band, desirably a band having an upper endand an apical end and a length extending from the upper end to theapical end and where the length of the band is less than about ⅓ lengthof a heart to which it is applied, and preferably having a lengthsubstantially matching the width of the A-V groove on the heart to whichit is applied.

[0012] The device may be an enclosure generally conforming in shape toat least a portion of an epicardium and having an upper end and anapical end and a length extending from the upper end to the apical endand having one or more, sometimes multiple, ribs extending from theupper end to the apical end.

[0013] The device may be a sack having a closed end, perhaps sized to bepositioned along the heart from the apical end (where it is applied) andless than about ⅓ length of that heart.

[0014] Another important variation: the inventive support may be made upof at least one flexible member introducable into the pericardial spaceand configured to have a generally linear delivery shape but totransform into a generally helical form upon introduction into thatpericardial space. The flexible member(s) may be ribbon-like membershaving the aspect ratios mentioned above. The ribbon-like member ormembers may have a flexibility and or thickness that varies along theirlength. The flexible member may have a lumen extending from the proximalend at least partially to the distal end and have at least one orificesituated to open to other surfaces of the generally helical member whenthe support is helically configured. Glue or adhesives may be passedthrough the lumen and the orifices. the glue may be selected so that itcauses adherence only between portions of the generally helical member.The glue may comprise a modified cyanoacrylate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is an anterior view of the heart in the human chest.

[0016]FIG. 2 is a posterior view of the heart showing placement of onevariation of the inventive device.

[0017]FIG. 3A shows a cross-sectional view of the compliant membermaking up one variation of the invention. FIG. 3B shows a side-view ofthe FIG. 3A device.

[0018]FIGS. 4 and 5 show various side-views of variations of theinvention.

[0019]FIG. 6A shows a side view of the compliant member making up onevariation of the invention. FIG. 6B shows a cross-sectional view of theFIG. 6A device.

[0020]FIGS. 5 and 6 show cross-sectional views of, respectively,mechanical fasteners and adhesives in placing the inventive device onthe pericardium.

[0021]FIGS. 7, 8, and 9 show various side-views of variations of theinvention.

[0022]FIGS. 10A, 10B, 11A, and 11B show close-ups of various webbingvariations suitable for the inventive device.

[0023]FIG. 11A shows a cross sectional view of a flexible member havinga non-adhering surface. FIG. 11B shows a woven fabric, also a side viewof the FIG. 11A fabric.

[0024]FIG. 12A shows a cross sectional view of a flexible member havinga composite non-adhering surface. FIG. 12B shows a non-woven fabric,also a side view of the FIG. 12A fabric.

[0025]FIG. 13A shows a side view of a device that is introduced into thepericardial space as shown and forms a helix upon introduction. FIG. 13Bshows a cross-section view of the FIG. 13A device.

[0026]FIG. 14 shows a variation of the FIGS. 13A and 13B device.

[0027]FIG. 15 shows a side view of the FIG. 14 device after introductionof the device and forming into a unitary support.

[0028] FIGS. 16A-16E show a method for introducing the inventive deviceinto contact with the epicardium.

DESCRIPTION OF THE INVENTION

[0029] As noted elsewhere, this invention includes a device forsupporting and constraining the epicardium during at least diastoly. Thedevice preferably has either: 1.) a generally sack-like shape (with orwithout an opening at the apical end of the sack) that is adapted to fitadjacent at least a portion of the epicardial wall and has one or moreribs integral to or cooperating with the sack and most preferably wherethose ribs are one or more helical ribs, or 2.) at least one rib thatwill encircle the heart and preferably binds to itself afterintroduction to the vicinity of the epicardial surface. Also includedare methods of introducing the inventive reinforcing device to thepericardial space.

[0030] First, in FIG. 1, the placement of a typical human heart (100) ina chest may be seen. Of special interest here is the pericardial space(102) filled with a pericardial fluid surrounding the epicardium (104).The pericardial sac (106) approaches the diaphragm (108) closely at theapex or apical end of the heart. In individuals who are not obese, thedistance from the exterior surface of the skin, through the diaphragm(108), and into the pericardial space (102) may be as short as a coupleof inches. In obese individuals, the distance may be much greater, e.g.,six inches or more. As will be discussed below, this sub-xiphoidapproach (a percutaneous route as described above, but below the xiphoidprocess—not shown in FIG. 1) is highly desirable and even preferable to“cracking the chest” to introduce various implants into the cardiacspace.

[0031] Also seen in FIG. 1 for reference are the lungs (110, 112) andthe ribs (114). Note how far below the apex of the heart (100) the ribsextend.

[0032]FIG. 2 shows a posterior view of the heart (100) with a variationof the inventive device (120) installed. From this view of the heart,the pericardial reflection (122) may be seen, as well as a majority ofthe passageways that connect the heart to the remainder of the vascularsystem. The inferior vena cava, the right pulmonary veins and the leftpulmonary veins (128) may be seen. The pulmonary arteries (130) and theaortic arch (132) are also visible. When the inventive device isintroduced into the pericardial space (102) in FIG. 1, the upperplacement of the device is defined by the pericardium and the situationof the grand veins and grand arteries. The placement of the inventivedevice (120) shown in FIG. 2 is for the purpose of depicting a preferredsiting of the device onto the epicardial or ventricular surface (136).This variation (120) includes a helically conformed rib (140) separatedand held together by at least one webbing member (142).

[0033] The inventive device provides support to the ventricular wall andfurther is intended to limit the radial movement of the heart wallduring diastoly. By limiting the expansion of the heart, the heart willremodel to supply blood to tissues as needed by strengthening theaffected muscles or by increasing the heart rate. Prior to thisremodelling, there may be intermediate problems with lessening of theejection fraction if the heart muscle is insufficiently strong to ejectthe normal percentage of its internal volume and allows the heart topump blood more efficiently. The inventive device does provide a measureof benefit in this circumstance in that it limits the blood volumeintroduced into the chamber.

[0034]FIGS. 3A and 3B show, respectively, a top cross-sectional view anda side view of a ribbed variation (150) of the invention. This variation(150) includes ribs (156) that extend from an upper (but optional) band(158) to an apical end (160). As may be seen in FIG. 3A, the ribs (156)may be semicircular in cross-section. Although there is a preference forthe interior of the ribs (156) to be a shape conformable to theepicardium, the cross-sectional shape of the ribs is not seen to beparticularly important. The ribs (156), as shown in FIGS. 3A and 3B, maystand alone but preferably are separated and held in place by webbing(152) of any of the various forms discussed herein.

[0035]FIG. 4 shows a side view of a variation of the pericardialreinforcement device (160) that is open in the end normally near theapical end of the heart and generally is band-shaped. Optional upper andlower ribs or bands (162) are included. These bands (162) are to providestructure to the often more-loosely woven compliant member (163)separating them. This variation (160) is especially suitable forproviding support locally to the ventricular valves, a region whosereinforcement is especially effective in alleviating congestive heartfailure. This variation minimizes the mass of material implanted intothe heart region, an often desirable result. A schematic introducer(164) is shown. The introducer (164) may be used to place the deviceinto an appropriate position using the procedures discussed elsewhere.

[0036]FIG. 5 shows a side view of a variation of the inventivereinforcement (165) having a generally epicardial form due to thepresence of webbing (166). Webbing (166) may be fabric, individualthreads, cords, etc—many of which are discussed elsewhere herein, butdesirably the webbing is formed in such a way as to allow for ease offolding and conformation during delivery of the device near and past theheart's apical end. The rib (167) is a single one that forms a helicalform when deployed. A schematic delivery wire or introducer (168) isshown.

[0037]FIGS. 6A and 6B show, respectively, a side view and across-sectional view of another ribbed variation (170). As was notedjust above, the ribs (172) are not semi-circular in cross-section buthave more of a flat aspect. In this variation, the ribs extend to anapical end (174). A schematic introducer (176) is shown. The ribs (172)may be separated by webbing (178) if desired.

[0038]FIG. 7 shows a side view of a variation (200) having ribs (202)that do not extend to the apical end, but instead stop at a lower band(204) and extend from an upper band (206). As was the case with theother variations of this type, the ribs may be separated by webbing(208). An introducer (210) is shown.

[0039]FIG. 8 shows a ribbed variation (220) of the inventive member inwhich the compliant member has ribs (222) that are zig-zag in shape.This rib variation minimizes the amount of material that is introducedas rib material but distributes the stiffer reinforcing material aroundthe periphery of the devices quite nicely. The ribs (222), again, may beseparated by webbing (224) material of the type discussed elsewhere. Anintroducer (226) is also shown. The ribs (232) are shown to be situated“in phase” but need not be. Other convoluted forms to the ribs, e.g.,sine shaped ribs, U-shaped ribs, etc., are also within the scope of theinvention.

[0040]FIG. 9 shows a side view of a variation (230) of the inventionwhere the ribs (232) are joined at their respective apexes. The ribs(232) thereby form a continuous cage about the reinforcing member (230).The various spaces (234) remaining amongst the ribs (232) may be filledwith ribbing (234) if so desired.

[0041] FIGS. 10A-10D show a number of variations of the “webbing”discussed above.

[0042]FIG. 10A shows a number of ribs (250) separated by and heldtogether by strands (252) of an appropriate material. The strands (252)collectively making up the webbing may be single threads or collectionsof threads making up a cord-like assemblage.

[0043]FIG. 10B shows the ribs (250) with a woven cloth (254) as thewebbing material. The relative pic value may be in a range that extendsbetween closed cloth to very open weave.

[0044]FIG. 10C shows the ribs (250) with a non-woven fabric (256) havingoptional upper and lower bands (258).

[0045] Finally, FIG. 10D shows ribs (250) separated by webbing (260)that is made up of a series of tapes (262) in turn formed from a fabric,woven or non-woven.

[0046] In addition to the generally pre-formed structures discussedabove, we contemplate that such structures be formable within thepericardial sac as they are applied to the epicardium.

[0047] All of our variations are passive devices.

[0048]FIG. 11A depicts a cross-section of a flexible member (300) havingan inner surface (302) that preferably does not adhere (or tends not toadhere) to the epicardium and also having an outer surface (304). Inthis variation of the invention, the inner surface (302) is coated witha material that tends not to form adhesions with the epicardium. Thenon-adhering material may be sprayed on or infused into anothersubstrate having a differing proclivity for adhesion onto heart tissue.

[0049] Incidentally, FIG. 11B show a typical woven fabric (304). Theweave need not be as loose as is shown in FIG. 11B. It is also withinthe scope of this invention to use a random fabric or “non-woven” (as itis known in the polymer industry) A non-woven material (306) is shown inFIG. 12B in another variation of the invention for another purpose, butmay be coated or used as a laminate member for the inventive device.

[0050] The material used that substantially prevents adhesion to theepicardium may be solid lubricious polymers such as polyfluorocarbonsand polyolefins selected from the group consisting ofpolytetrafluoroethylene (PTFE or TFE), ethylene-chlorofluoroethylene(ECTFE), fluorinated ethylene propylene (FEP),polychlorotrifluoroethylene (PCTFE), polyvinylfluoride (PVF),polyvinylidenefluoride (PVDF), polyethylene (LDPE, LLDPE, and HDPE), andpolypropylene. Other polymers such as the Nylons and polysulphones arealso acceptable.

[0051] Again, these polymers may be applied in a variety of ways, e.g.,as emulsions, dispersions, or solutions, to another substrate materialas a covering or as an infusion or the substrate material may insteadcomprise the substantially non-adhering material.

[0052]FIG. 12A shows a cross-section of variation (310) of the inventivedevice in which the inner surface (316) is a layer separate from thelayer (318) adjacent the pericardium. The two layers (310) may belaminated together, if so desired. They need not be, since the functionof the non-adhering side (316) is simply to prevent attachment of theepicardium to the inventive device. Again, both layers (314, 316) may bewoven, non-woven, or a mixture as desired by the designer.

[0053] As is shown in FIG. 12A, the two surfaces (312, 316) may beindependent structures, but may also be fixedly laminated together.

[0054] In addition to the webbed variations discussed here, theinvention includes variations either not having webbing between the ribsor variations in which one or more ribs are introduced into thepericardial space and form a unitary structure once placed there. Inparticular, the non-webbed variations desirably include an adhesivewhich is specially adapted not to adhere to human tissue butspecifically to adhere to itself and to certain selected polymers. Oncesuch way of producing an aggregate whole would be to use the materialsdescribed in Published International Application WO-00/44287 owned byProhold Medical Technologies, Inc. Such publication describes a modifiedcyanoacrylate polymer which, for instance, may be applied in itsconstituent parts in such away that when the two constituent componentsare applied to different parts of, e.g., the introduced rib discussedelsewhere with regard to FIGS. 13A, 13B, 14, and 15, the device tends tostick to itself and form an integral or unified device when placed incertain ionic environments.

[0055] In any case, FIGS. 13A and 13B show, respectively, a side viewand a cross-sectional view of a device (340) which may be introducedinto the pericardial space through a large catheter or through a cannulaor the like. The device may be pre-formed so that as it is introducedinto the pericardial space, it self-forms into a helical rib, much aswas shown with respect to FIG. 5 above, but without the attachedwebbing. Preferably, the device (340) includes a first side (342) havinga number of orifices (344) penetrating that side into an expandablelumen. The lumen opens upon introduction of some material into theregion between the first side (342) and the opposing second side (346).A pre-formed and/or pre-formable stiffener (348) is shown, particularlyin FIG. 13B. This pre-formed member aids in the curving formation of thedevice after introduction into the pericardial space.

[0056] It is within the scope of this invention that the stiffenercomponent (348) be removable after the device has been situated andglued or otherwise formed into an integral whole as is shown in FIG. 2or 15. Further, the devices shown in FIG. 13A prior to being introducedinto the space around the heart includes a lumen (350) for introducing afluid into the interior of the device (340) and a joint (352) forseparating the implant portion of the device (340) from the introducersection (354) that includes the delivery lumen (350).

[0057] Delivery lumen (350) may be used, for instance, for introducingone or more appropriate glues or adhesives into the device in such a waythat it leaves or exudes through the various orifices (344), preferablyin such a way that it sticks the sides of the device after it has beencurled into an overlapping helix onto itself.

[0058]FIG. 14 shows another variation of the inventive device (360)having a central rib section (362) and a number of ancillary ribs (364)having orifices (366), preferably on but one side of the device. Thevariation also includes separable joint (366) and introducer (368),preferably having a delivery lumen (370). Again, the body or central rib(362) preferably is pre-formed in such a way that, upon introductioninto the pericardial space, the central rib (362) wraps about the heartin a helical fashion as it is physically introduced. The ancillary ribs(364) preferably would overlap in such a way as may be seen in FIG. 15so that upon introduction of a glue or appropriate adhesive into thedelivery lumen (370) and out of the orifices (366) that the overlappingancillary ribs form an interlocking adhered together tubular assembly(372).

[0059] Obviously, the simpler device shown in FIGS. 13A and 13B also areformable into a glued-together helical rib, generally tubular member forcontact with the epicardium. Again, as noted above, the devices onceintroduced into the pericardial space, should be placed in contact withthe epicardium and allowed to form into an appropriate size and providethe appropriate amount of constraint or restraint of the appropriatecycle of the heartbeat.

[0060] This inventive device is neat and because it is situated incontact with the epicardium, is suitable for placement via any number ofprocedures, ranging from the most invasive—open chest surgery—to thosethat are much less invasive. A preferred procedure for placing thedevice is via a percutaneous approach potentially through the diaphragmbeneath the xiphoid process. It is direct and uses short instruments forease and accuracy. One highly desirable method for placement of theinventive reinforcement is shown in FIGS. 16A-16E.

[0061] Shown in FIG. 16A is a heart (380) having an epicardial surface(382) surrounded by a pericardial space (384) holding pericardial fluidand all enclosed by the pericardium (386). The muscle sheet known as thediaphragm (388) may also be seen. For the purposes of depicting thespatial relationships in this procedure, the xiphoid process (510) isshown in shadow. All of the extraneous body parts not needed here forexplanation of the procedure have been deleted for clarity.

[0062] Also shown in the first step of the procedure, is a needle (392)Much of the extraneous body structure not otherwise needed forexplanation of the procedure have been omitted for clarity.

[0063] Also shown in FIG. 16A is the first step of the procedure. Asuitably large hollow needle (392) and a guidewire (394) passing throughthe lumen of the needle (392) have been introduced below the xiphoidprocess (390) and through the diaphragm (388). The needle (392) and theguidewire (394) are shown having penetrated the pericardium (386). Thedistal end (396) of the guidewire (394) is shown passing up through thepericardial space to the upper end of the heart.

[0064]FIG. 16B shows that the needle has been removed from the guidewire(394) and the distal end (396) of the guidewire (394) has beenmanipulated to pass upwardly and across the epicardial surface of theheart. An introducer or cannula (398) is shown being passed up theguidewire (394).

[0065] In FIG. 16C, the introducer or cannula (398) has been placedthrough the pericardium (386) and the delivery catheter (400) has beeninserted and may be seen proceeding towards the proximal end of theintroducer or cannula (398).

[0066]FIG. 16D shows the placement of the delivery catheter (400) priorto introduction of the inventive device with the catheter's distal endplaced on an upper region of a ventricular wall needing support orconstraint. One will note that the guidewire has been removed.

[0067]FIG. 16E shows the emergence of the inventive device (404) fromthe distal end of the catheter (400) and the beginning of the passage ofthe distal end (406) around the heart again.

[0068] The inventive device (424) should follow the contours of theepicardium until it reaches its desired site as shown in FIG. 16F. Avibratory or oscillatory motion may be desirable to urge the device toits final spot.

[0069] In FIG. 16F, the catheter (400) and the introducer (398) havebeen removed and their access points repaired, leaving the device (404)against the epicardial surface for support.

[0070] Many alterations and modifications may be made by those ofordinary skill in this art, without departing from the spirit and scopeof this invention. The illustrated embodiments have been shown only forpurposes of clarity and the examples should not be taken as limiting theinvention as defined in the following claims. Which claims are intendedto include all equivalents, whether now or later devised.

We claim as our invention:
 1. A flexible passive support forconstraining epicardial expansion past a predetermined limit comprisinga flexible member comprises an enclosure generally conforming in shapeto at least a portion of an epicardium and the enclosure comprising atleast one rib separated by and spaced by webbing, the at least one ribhaving a flexibility differing than the webbing flexibility.
 2. Theflexible passive support of claim 1 where the at least one rib comprisesa generally helical member.
 3. The flexible passive support of claim 2where the generally helical member comprises a ribbon-like member. 4.The flexible passive support of claim 3 where each at least one ribcomprises a ribbon-like member.
 5. The flexible passive support of claim4 where each ribbon-like member has a width-thickness ratio greater thanabout two.
 6. The flexible passive support of claim 4 where eachribbon-like member has a width-thickness ratio greater than about seven.7. The flexible passive support of claim 2 where the generally helicalmember is inflatable over at least a portion of the enclosure.
 8. Theflexible passive support of claim 2 where the generally helical memberis incrementally inflatable.
 9. The flexible passive support of claim 1where the flexible member comprises an enclosure generally conforming inshape to at least a portion of an epicardium and having an upper end andan apical end and a length extending from the upper end to the apicalend and having multiple ribs extending from the upper end to the apicalend.
 10. The flexible passive support of claim 9 where the multiple ribsare each ribbon-like.
 11. The flexible passive support of claim 10 whereeach ribbon-like member has a cross section with a width-thickness ratiogreater than about two.
 12. The flexible passive support of claim 11where each ribbon-like member has a cross section with a width-thicknessratio greater than about seven.
 13. The flexible passive support ofclaim 9 where the multiple ribs each have a round cross section.
 14. Theflexible passive support of claim 9 where the multiple ribs each have across section with a width-thickness ratio of two or less.
 15. Theflexible passive support of claim 9 where the multiple ribs are eachzigzag in shape.
 16. The flexible passive support of claim 15 where themultiple zigzag ribs have substantially adjacent points and at leastsome of the adjacent points are connected.
 17. The flexible passivesupport of claim 9 where at least some of the multiple ribs are joinedat the apical end.
 18. The flexible passive support of claim 1 where thewebbing comprises a woven fabric.
 19. The flexible passive support ofclaim 1 where the webbing comprises a woven, open weave fabric.
 20. Theflexible passive support of claim 1 where the webbing comprises anon-woven fabric.
 21. The flexible passive support of claim 1 where thewebbing comprises one or more ribbons extending between at least some ofthe multiple ribs.
 22. The flexible passive support of claim 1 where thewebbing comprises one or more fibers extending between at least some ofthe multiple ribs.
 23. The flexible passive support of claim 1 where thewebbing comprises an elastic material.
 24. The flexible passive supportof claim 1 where the webbing comprises a substantially inelasticmaterial.
 25. The flexible passive support of claim 1 where the flexiblemember comprises a band.
 26. The flexible passive support of claim 1where the flexible member comprises a band having an upper end and anapical end and a length extending from the upper end to the apical endand where the length of the band is less than about ⅓ length of a heartto which it is applied.
 27. The flexible passive support of claim 25where the a band has a length substantially matching the width of an A-Vgroove on a heart to which it is applied.
 28. The flexible passivesupport of claim 1 where the flexible member comprises a sack having aclosed end.
 29. The flexible passive support of claim 28 where theflexible member comprises a sack having a closed end and sized to bepositioned along of an apical end of heart to which it is applied andless than about ⅓ length of that heart.
 30. The flexible passive supportof claim 1 where the flexible member comprises a material selected notto adhere to the epicardium.
 31. The flexible passive support of claim30 where the flexible member has a side selected to be positionedadjacent the epicardium which side has a non-adherent surface comprisinga non-adherent material that tends not to form adhesions with theepicardium.
 32. The flexible passive support of claim 31 where thenon-adherent surface has been formed by spraying a non-adherent materialonto the side.
 33. The flexible passive support of claim 31 where thenon-adherent surface has been formed by infusing a non-adherent materialinto the side.
 34. The flexible passive support of claim 31 where thenon-adherent surface comprises a separate layer of a non-adherentmaterial that tends not to form adhesions with the epicardium.
 35. Theflexible passive support of claim 31 where the non-adherent sidecomprises a separate layer of a non-adherent material is not laminatedto other layers in the flexible member.
 36. The flexible passive supportof claim 31 where the non-adherent side comprises a separate layer of anon-adherent material is laminated to at least one other layer in theflexible member.
 37. The flexible passive support of claim 31 where thenon-adherent material comprises at least one polymer that tends not toform adhesions with the epicardium.
 38. The flexible passive support ofclaim 31 where the non-adherent material comprises solid lubriciouspolymers selected from the group consisting of polyfluorocarbons andpolyolefins.
 39. The flexible passive support of claim 31 where thenon-adherent material comprises one or more polymers selected from thegroup consisting of polytetrafluoroethylene (PTFE or TFE),ethylene-chlorofluoroethylene (ECTFE), fluorinated ethylene propylene(FEP), polychlorotrifluoroethylene (PCTFE), polyvinylfluoride (PVF),polyvinylidenefluoride (PVDF), polyethylene (LDPE, LLDPE, and HDPE), andpolypropylene.
 40. The flexible passive support of claim 31 where thenon-adherent material comprises one or more polymers selected from thegroup consisting of the Nylons and polysulphones.
 41. A flexible passivesupport for constraining epicardial expansion of a heart past apredetermined limit comprising at least one flexible member introducableinto a pericardial space and configured to have a generally lineardelivery shape and further configured to transform into a generallyhelical form upon introduction into that pericardial space.
 42. Theflexible passive support of claim 41 where the at least one flexiblemember comprises a ribbon-like member.
 43. The flexible passive supportof claim 42 where each ribbon-like member has a width-thickness ratiogreater than about two.
 44. The flexible passive support of claim 43where each ribbon-like member has a width-thickness ratio greater thanabout seven.
 45. The flexible passive support of claim 42 where the atleast one ribbon-like member has a length and varies in flexibilityalong that length.
 46. The flexible passive support of claim 42 wherethe at least one ribbon-like member has a length and varies in widthalong that length.
 47. The flexible passive support of claim 42 wherethe at least one ribbon-like member has a length and varies in thicknessalong that length.
 48. The flexible passive support of claim 42 wherethe generally helical member is at least partially inflatable.
 49. Theflexible passive support of claim 48 where the generally helical memberis incrementally inflatable.
 50. The flexible passive support of claim41 where the at least one flexible member comprises multiple ribbon-likemembers.
 51. The flexible passive support of claim 42 where thegenerally helical member has a lumen extending from the proximal end atleast partially to the distal end.
 52. The flexible passive support ofclaim 42 where the generally helical member includes at least oneorifice situated to open to other surfaces of the generally helicalmember when the support is helically configured.
 53. The flexiblepassive support of claim 52 where the generally helical member furthercomprising a source of glue or adhesive flowable through the at leastone orifice, the glue or adhesive suitable for causing adherence onlybetween portions of the generally helical member.
 54. The flexiblepassive support of claim 53 where the glue or adhesive comprises amodified cyanoacrylate.
 55. A method for supporting the epicardiumcomprising the steps of: a.) introducing the passive support of claim 1below a xiphoid process through a pericardium wall into a pericardialspace, and b.) positioning the passive support adjacent the epicardium.56. The method of claim 55 further comprising the steps of puncturingskin beneath the xiphoid process with a needle and passing the needleand a guidewire through the pericardium into the pericardial space. 57.The method of claim 56 further comprising the steps of withdrawing theneedle and introducing an introducer over the guidewire through thepericardium into the pericardial space
 58. The method of claim 57further comprising the step passing a delivery catheter through theintroducer over the guidewire through the pericardium into thepericardial space to a site adjacent an epicardium.
 59. The method ofclaim 57 further comprising the subsequent step of introducing thepassive support through the delivery catheter to the epicardium.